Lecture 2 Pt 2

Question 1

BSP

Answer 1

a group of pops that have the potential to interbreed in nature to produce fertile offspring

Question 2

Bsp limitations

Answer 2

subspecies
based on infertility rather than physical similarity
doesn’t work for asexual species
over-emphasis on gene flow
downplays role of natural selection

Question 3

Morphological Species Concept

Answer 3

concept defines a species based on its physical characteristics

Question 4

Ecological Species concept

Answer 4

based on how an organism interacts with its ecosystem

Question 5

Phylogenetic species concept

Answer 5

based on common ancestry

Question 6

Evolution leading to speciation involves

Answer 6

increasing in genetic variation ex mutations + allele shuffling

Question 7

Reproductive isolation

Answer 7

heritable diffs that block interbreeding between pops

Question 8

Speciation

Answer 8

process by which one species split into 2 or more
+ branching point

Question 9

Genetic Divergence

Answer 9

Differences build up between gene pools

Question 10

Reproductive Barrier

Answer 10

anything that prevents interbreeding between pops

Question 11

Prezygotic (prevents fertilization) barrier: Mechanical isolation

Answer 11

diffs in structure/function of reproductive organs prevent fertilization

Question 12

Prezygotic barrier : Temporal isolation

Answer 12

timing of reproduction (“mating seasons”) prevents fertilization

Question 13

prezygotic barriers : behavioral isolation

Answer 13

Complex courtship rituals that precede mating

Question 14

Prezygotic Barriers: ecological / habitat isolation

Answer 14

diffs micro-environment within same habitat never meet

Question 15

Prezygotic barriers: Gametic isolation

Answer 15

incompatibilities between sperm and egg
ex: broadcast spawning
specific molecules on gametes that facilitate fertilization

Question 16

Post zygotic barriers: reduced hybrid viability

Answer 16

fertilization occurs, but zygote may not give rise to functioning healthy adults

Question 17

post zygotic barriers: reduced hybrid fertility

Answer 17

hybrid is sterile

Question 18

Mechanisms of speciation

Answer 18

requires some kind of cut-off between pops

Question 19

Allopatric speciation

Answer 19

Geographically isolated pops cannot interbreed

Question 20

Sympatric speciation

Answer 20

2+ pops coexist, ecological and behavioral genetic barriers lead to speciation. more common in plants

Question 21

Adaptive radiation

Answer 21

orgs diversify rapidly from ancestral species, often due to changes in enviro

Question 22

Gradualism

Answer 22

steady accumulation of small individual changes

Question 23

punctuated equilibrium

Answer 23

major changes take place in spurts followed by periods of stasis